Fluorine-containing polymers have been long known and have been used in a variety of applications because of several desirable properties such as heat resistance, chemical resistance, weatherability, UV-stability, etc.
Further, it is known that branching in polymers can result in desirable properties. For example, these polymers can have favorable rheological properties relative to their linear counterparts.
Bifunctional comonomer and halogenated comonomers have been used to cause branching of a fluoropolymer during polymerization. For example, U.S. Pat. No. 5,585,449 (Arcella, et al.) discloses the use of bisolefins to achieve long chain branching, while U.S. Pat. No. 7,375,157 (Amos et al.) discloses the use of halogenated olefins to cause branching of a fluoropolymer during polymerization.